F128 error on a GE dishwasher: A troubleshooting guide

If the F128 error on your GE dishwasher is interrupting your cleaning routine, there’s most likely a problem with the rinse aid dispensing system. This is an easy DIY fix that shouldn’t take very long.

If you find out that you need replacement parts for your GE dishwasher, you can enter your model number at AppliancePartsPros.com to order them. Most orders arrive in just two business days, and we have thousands of free guides to show you how to install your new parts.

Let’s get your dishwasher working smoothly again!

Disclaimer: The error code information provided in this article is based on general service manuals and may not apply to your specific appliance model. While we strive to offer helpful advice for DIY appliance repairs, variations in models and configurations can lead to differences in troubleshooting steps, error codes, and part replacements. For the most accurate guidance, we strongly recommend consulting the technical sheet for your specific appliance model.

What causes an F128 error?

GE dishwasher fault code F128 is usually triggered when the rinse aid level runs low. Rinse aid is an important part of the wash cycle that reduces beading and streaking on dishes and glassware. The rinse aid is held in a storage tank inside the detergent dispenser.

The rinse aid tank can hold about 100 mL or 3.5 oz of liquid. As rinse aid is used during each cycle, the level eventually drops low enough to trigger the F128 sensor fault. On dishwashers with an LCD, the code will show on the screen. Models with indicator lights will blink the “Rinse Aid” LED light.

In either case, F128 means it’s time to refill the rinse aid reservoir. But if the code persists after topping off the tank, you’ll have to continue troubleshooting.

Read more: Dishwasher Not Fully Cleaning Dishes: Top 5 Reasons & Fixes

Keep safety first

Your safety should always be the top priority when performing any appliance repair.

• Always power off and unplug your appliance or switch off the circuit breaker before you attempt any maintenance or replacement work. This keeps you safe by preventing any risk of electric shock.
• Turn off the water supply at the outlet before beginning repairs. Keep towels ready to catch any residual water in the system when removing parts.
• Take your time while working to prevent accidents and personal injuries. Rushing is the enemy of precision.
• Work in a well-lit area so you can clearly see and access appliance parts.
• Keep your workspace free of clutter and other obstacles. Keep children and pets away from the work area.
• Never work on internal parts with wet hands. Make sure the work area is completely dry.
• Check the user manual to see if there are specific installation or safety instructions related to your appliance or replacement part.
• Be gentle when handling or removing parts. Excessive force might damage the appliance or cause personal injury.
• When working with wires, avoid touching any exposed wires or terminals. If you need to touch a wire, use a non-conductive tool or wear insulating gloves to prevent electrical shock.
• Don’t test live voltage with a multimeter if you’re unfamiliar with how to prevent short-circuiting.

Step 1 – Check the rinse aid tank

Whenever F128 appears, the first thing to check is the rinse aid reservoir.

1. Find the fill cap inside the detergent dispenser.
2. Unscrew the cap and inspect the tank.

If the reservoir is empty, fill it with a good quality rinse aid formulated for dishwashers. Make sure to tighten the fill cap completely when you’re done.

If there is rinse aid present, try cleaning the tank. Mineral deposits inside the tank can interfere with the level sensor. You can run hot water through the reservoir while shaking it gently to dissolve any buildup. Soak stubborn deposits with white vinegar before you rinse it clean, then refill with fresh rinse aid.

Read more: What is Dishwasher Salt: How to Use it & Benefits

Step 2 – Check the dispenser

1. With the rinse aid door open, inspect it for any residue build-up.
2. Clean any residue buildup with white vinegar and flush with water.
3. Make sure all gaskets are in good condition and not deteriorated in any way.
4. Initiate a normal wash cycle and allow the dishwasher to run through the complete sequence.
5. Check the dishes to see if the rinse aid was dispensed during the final rinse. You should see minimal to no water beading on your dishes. If many beads of water remain and the dishes take longer than normal to dry, then the rinse aid wasn’t dispensed. The F128 code will likely reappear in the next cycle, so you should continue troubleshooting.

Step 3 – Access the dispenser wiring

1. Turn off the dishwasher and unplug it.
2. Remove the inner door panel to access the rinse aid dispenser wiring.
3. Detach the dispenser harness connector from the main user interface (UI) control board.
4. Release the locking tab to separate the plug.
5. Unplug the wiring at the moisture sensor that’s attached to the rinse aid reservoir.
6. Look over all connectors for corrosion or damage. Clean them with an electrical contact cleaner or replace them if needed.

Step 4 – Check the voltage

LIVE VOLTAGE WARNING: For this test, the dishwasher needs to be plugged in and powered on. Please be very careful to protect yourself from electric shock, which has the potential to cause serious injuries. Don’t ever test live voltage if you’re uncomfortable using a multimeter.

1. Reconnect the dispenser wiring.
2. Restore power and water to the dishwasher.
3. With the front panel off, open the dishwasher door.
4. Set a multimeter to volts DC.
5. After closing the door, use the meter leads to check for 1 volt DC at the sensor terminals from the blue/black wire to the tan/yellow wire.
6. Check the meter reading. If there’s no voltage, replace the UI control board. If you get 1 volt DC, continue to the next step.
7. Use the meter leads to check the rinse sensor terminals from the black/green wire to the tan/yellow wire. A meter reading of 3 – 5 volts DC is normal for a full tank. 0.5 – 2 volts DC indicates a low/empty reservoir. If the reading is outside the acceptable range, replace the dispenser module.

Read more: Surprising Things That Can & Can’t Go in the Dishwasher

Step 5 – Test the dishwasher

After any repairs are made, test the rinse aid function in your dishwasher:

1. Fill the reservoir with rinse aid.
2. Reconnect the water supply to the dishwasher and plug it in.
3. Initiate a wash cycle and let it run the full time.
4. Inspect the dishes for excessive beading, spots, or streaks.

Read more: How to Clean a Dishwasher

More information

Thank you for reading! We hope this guide helped you get your GE dishwasher working again.

If you have any other appliance repair needs or projects, don’t hesitate to explore our thousands of free videos and troubleshooting guides available. If you need replacement parts or some extra help, grab your model number and head over to AppliancePartsPros.com, where you can chat with a pro, order parts, read our DIY blog, and more. We can also help you troubleshoot common dishwasher problems here.

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